In what literary element of a spiritual will you most likely find its key ideas?
a. refrain
c. solo lyrics
b. opening line
d. title

The right answer is "a. refrain ".

The explanation for this answer is that the refrain serves to reaffirm to those who are reading, the meaning of the work, then there will be the key words for the understanding of that meaning. In the case of the unison poem it is used to affirm the thought that is expressed. It better explains the main meaning of the poem.

the answer is:

when will (v) the books (n) be (v) due?

nouns refer to people (other than pronouns), places and things, whereas verbs describe actions and are usually part of the predicate of a sentence. finally, pronouns can work as nouns and identify the participants in speech.

in the example sentence, "will" is a verb part or auxiliary verb, "be" is an infinitive verb and "books" is a plural noun.

the 2nd and 4th are correct